Food Science Commons^™

Cultivation Of Stable, Reproducible Microbial Communities From Different Fecal Donors Using Minibioreactor Arrays (Mbras), Jennifer M. Auchtung, Catherine D. Robinson, Robert A. Britton

Department of Food Science and Technology: Faculty Publications

Background: Continuous-flow culture models are one tool for studying complex interactions between members of human fecal microbiotas because they allow studies to be completed during an extended period of time under conditions where pH, nutrient availability, and washout of waste products and dead cells can be controlled. Because many of the existing well-validated continuous-flow models are large and complex, we were interested in developing a simpler continuous-flow system that would allow microbial community dynamics to be examined in higher throughput while still maintaining complex microbial communities. To this end, we developed minibioreactor arrays (MBRAs), small volume bioreactors (15 ml) that …

Stalk Strenght And Sugar Content Of 55 Dual-Purpose Sorghum Inbreds, S. F. Chen, M.-G. C. Danao, P. J. Brown

Department of Food Science and Technology: Faculty Publications

In 2012, sorghum was approved by the U.S. Environmental Protection Agency (EPA) as an “advanced” bioenergy feedstock in cases where both the grain and stover are both used for energy production (USEPA, 2012). It is desirable, therefore, to develop taller varieties of sorghum to increase biomass yields. However the taller the plant gets, the more susceptible it becomes to lodging, reducing grain yield in the end. Additionally the ability to characterize the storage stability of new sorghum varieties in terms of moisture content and free sugars content is advantageous. In this study, high throughput assays to characterize stalk strength based …

Preface, Metagenomics For Microbiology, Jacques Izard, Maria C. Rivera

Department of Food Science and Technology: Faculty Publications

It is well known that only a small fraction of extant microbial life has been identified. Metagenomics, the direct sequencing and characterization of genes and genomes present in complex microbial ecosystems (for example, metagenomes), has revolutionized the practice of microbiology by bypassing the hurdle of pure culture isolation. Metagenomics shows promise of advancing our understanding of the diversity, function, and evolution of the uncultivated majority.

Metagenomics as a field arose in the 1990s after the application of molecular biology techniques to genomic material directly extracted from microbial assemblages present in diverse habitats, including the human body. The application of metagenomic …

Metagenomics For Bacteriology, Erika Del Castillo, Jacques Izard

Department of Food Science and Technology: Faculty Publications

The study of bacteria, or bacteriology, has gone through transformative waves since its inception in the 1600s. It all started by the visualization of bacteria using light microscopy by Antonie van Leeuwenhoek, when he first described “animalcules.” Direct cellular observation then evolved into utilizing different wavelengths on novel platforms such as electron, fluorescence, and even near-infrared microscopy. Understanding the link between microbes and disease (pathogenicity) began with the ability to isolate and cultivate organisms through aseptic methodologies starting in the 1700s. These techniques became more prevalent in the following centuries with the work of famous scientists such as Louis Pasteur …

Promises And Prospects Of Microbiome Studies, Maria C. Rivera, Jacques Izard

Department of Food Science and Technology: Faculty Publications

Since Anthony van Leeuwenhoek, first microscopic observations of the unseen microbiota and the more recent realization that little of the microbes in the biosphere are known, humans have developed a deep curiosity to fully understand the inner workings of the microbial realm. Our ability to characterize the complexity of microbial communities in their natural habitats has dramatically improved over the past decade thanks to advances in high-throughput methodologies. By eliminating the need to isolate and culture individual species, metagenomics approaches have removed many of the obstacles that hindered research in the ecology of mixed microbial consortia, providing valuable information about …

How Good Is Good Enough? Data Requirements For Reliable Crop Yield Simulations And Yield-Gap Analysis, Patricio Grassini, Lenny G.J. Van Bussel, Justin Van Wart, Joost Wolf, Lieven Claessens, Haishun Yang, Hendrik Boogaard, Hugo De Groot, Martin K. Van Ittersum, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

Numerous studies have been published during the past two decades that use simulation models to assess crop yield gaps (quantified as the difference between potential and actual farm yields), impact of climate change on future crop yields, and land-use change. However, there is a wide range in quality and spatial and temporal scale and resolution of climate and soil data underpinning these studies, as well as widely differing assumptions about cropping-system context and crop model calibration. Here we present an explicit rationale and methodology for selecting data sources for simulating crop yields and estimating yield gaps at specific locations that …

Comparison Of Six Commercial Elisa Kits For Their Specificity And Sensitivity In Detecting Different Major Peanut Allergens, Shyamali Jayasena, Mieke Smits, Daniëlle Fiechter, Aard De Jong, Julie A. Nordlee, Joe Baumert, Steve L. Taylor, Raymond H. Pieters, Stef J. Koppelman

Department of Food Science and Technology: Faculty Publications

Six commercial peanut enzyme-linked immunosorbent assay kits were assessed for their ability to recover peanut from the standard reference material 2387 peanut butter and also for their specificity in detecting four major peanut allergens, Ara h 1, Ara h 2, Ara h 3, and Ara h 6. The percentage recovery of peanut from peanut butter differed across different kits as well as at different sample concentrations. The highest recovery was observed with the Romer and R-Biopharm kits, while four other kits were found to underestimate the protein content of the reference peanut butter samples. Five of the kits were most …

Atmospheric Cold Plasma As A Tool For Microbiological Control, Dana Ziuzina

Doctoral

Outbreaks of foodborne human illnesses resulting from contaminated raw or minimally processed fruits and vegetables have been widely reported globally. The microbiological challenges associated with fresh produce are diverse and respond differently to minimal processing technologies. Atmospheric cold plasma is a relatively new technology and represents a potential alternative to traditional methods for decontamination of foods. The objective of this work was to determine the influence of extrinsic atmospheric cold plasma (ACP) treatment control parameters and to optimize treatment parameters for decontamination with respect to different forms of key safety challenges pertinent to fresh produce.

The optimisation studies demonstrated that …

Characterization Of The Ecological Role Of Genes Mediating Acid Resistance In Lactobacillus Reuteri During Colonization Of The Gastrointestinal Tract, Janina A. Krumbeck, Nathan L Marsteller, Steven Frese, Daniel A. Peterson, Amanda Ramer-Tait, Robert W. Hutkins, Jens Walter

Department of Food Science and Technology: Faculty Publications

Rodent-derived strains of Lactobacillus reuteri densely colonize the forestomach of mice and possess several genes whose predicted functions constitute adaptations towards an acidic environment. The objective of this study was to systematically determine which genes of L. reuteri 100-23 contribute to tolerance towards host gastric acid secretion. Genes predicted to be involved in acid resistance were inactivated, and their contribution to survival under acidic conditions was confirmed in model gastric juice. Fitness of five mutants that showed impaired in vitro acid resistance were then compared through competition experiments in ex-germ-free mice that were either treated with omeprazole, a proton-pump inhibitor …

Steps In Metagenomics: Let’S Avoid Garbage In And Garbage Out, Jacques Izard

Department of Food Science and Technology: Faculty Publications

Is metagenomics a revolution or a new fad? Metagenomics is tightly associated with the availability of next-generation sequencing in all its implementations. The key feature of these new technologies, moving beyond the Sanger-based DNA sequencing approach, is the depth of nucleotide sequencing per sample.Knowing much more about a sample changes the traditional paradigms of “What is the most abundant?” or “What is the most significant?” to “What is present and potentially sig­nificant that might influence the situation and outcome?” Let’s take the case of identifying proper biomarkers of disease state in the context of chronic disease prevention. Prevention has been …

Effect Of Neighborhood Features On Bmi Of African American Adolescents In South Los Angeles, Francisca Omelogo Obiora

Walden Dissertations and Doctoral Studies

Childhood obesity is a major national and worldwide public health crisis. The occurrence of childhood obesity, caused to large extent by an imbalance between caloric intake and caloric expenditure, has increased in the last 30 years. Although the prevalence of obesity has stabilized in recent years, it remains a top public health concern in the United States, especially in urban centers. The purpose of this study was to examine the associations between diet, physical activity, and the built environment in relation to the mean body mass index (BMI) of adolescents aged 12 to 17 years living in South Los Angeles, …

Efficacy Of Ultraviolet Radiation To Control Lactic Acid Bacteria In Wine Must, Brian D. Williams

All Master's Theses

The use of shortwave ultraviolet (UV_c) radiation to control lactic acid bacteria (LAB) in wine production was studied. A simulated wine sterilizer was built using a commercially sourced ultraviolet (UV) sterilizer commonly used in aquariums and ponds. After growing cultures in test tubes, samples of five different species of LAB were introduced into white grape juice adjusted for brix and pH to match that of wine must commonly found in the Yakima Valley American Viticultural Area. The mixture was then agitated and allowed time to evenly distribute the bacteria throughout the juice. The juice was sent through the …

Bacterial Expression Of Plant Pyruvate Kinase, Kristina Fuller

STAR Program Research Presentations

Pyruvate kinases serve an important role in regulating glycolysis pathways. Different pyruvate kinase isozymes can dictate which of several different products will be formed during the final step of glycolysis. Being able to reliably copy active pyruvate kinases (PK) would allow study of the different isozymes, with the goal of eventually creating plants that are more nutritionally beneficial for humans. This study focused on improving the protocol for replicating each of two isolated PK isozymes from the model plant Arabidopsis thaliana. Previous attempts had resulted in the PK denaturing and consequently precipitating out of solution and so we manipulated the …

Growth Inhibitory Properties Of Lactose Fatty Acid Esters, Seung-Min Lee, Guneev Sandhu, M. K. Walsh

Nutrition, Dietetics, and Food Sciences Faculty Publications

Sugar esters are biodegradable, nonionic surfactants which have microbial inhibitory properties. The influence of the fatty acid chain length on the microbial inhibitory properties of lactose esters was investigated in this study. Specifically, lactose monooctanoate (LMO), lactose monodecanoate (LMD), lactose monolaurate (LML) and lactose monomyristate (LMM) were synthesized and dissolved in both dimethyl sulfoxide (DMSO) and ethanol. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined in growth media. LML was the most effective ester, exhibiting MIC values of

The Contribution Of Non-Thermal And Advanced Oxidation Technologies Towards Dissipation Of Pesticide Residues, N. Misra

Articles

Background

The use of pesticides has stabilised the food production to a great extent and their usage cannot be avoided anymore. Nevertheless, common food processing operations always allowed dissipating pesticide residues in foods to some extent. Within the food science community and the food processing sector, non-thermal food technologies are being researched and commercialised at a great pace over the past three decades.

Scope and Approach

In this review we provide a critical analysis of the literature pertinent to the fate of pesticide residues during non-thermal processing of solid and liquid foods. We also identify the opportunities for further development …

A Mathematical Model Of Meat Cooking Based On Polymer-Solvent Analogy, M. Chapwanya, Nissreen Misra

Articles

Mathematical modelling of transport phenomena in food processes is vital to understand the process dynamics. In this work, we study the process of double sided cooking of meat by developing a mathematical model for the simultaneous heat and mass transfer. The constitutive equations for the heat and mass transport are based on Fourier conduction, and the Flory–Huggins theory respectively, formulated for a two-phase transport inside a porous medium. We investigate a reduced one-dimensional case to verify the model, by applying appropriate boundary conditions. The results of the simulation agree well with experimental findings reported in literature. Finally, we comment upon …

Gas-Forming Nonstarter Lactorbacilli, Megan Jane Ostler, Jeff Broadbent, Craig J. Oberg, Donald J. Mcmahon

Nutrition, Dietetics, and Food Sciences Faculty Publications

An obligatory heterofermentative lactic acid bacterium Lactobacillus wasatchii sp. nov. isolated from gassy Cheddar cheese was studied for growth, gas formation, salt tolerance and survival against pasteurization treatments at 63°C and 72°C. Initially, Lb. wasatchii was thought to only use ribose as a sugar source and we were interested in whether it could utilize galactose. Experiments to determine rate and extent of growth and gas production in carbohydrate restricted (CR) de Man, Rogosa, and Sharpe (MRS) medium under anaerobic conditions with various combinations of ribose and galactose at 12, 23, and 37°C were conducted with 23°C being the more optimum …

Growth And Gas Production Of A Novel Obligatory Heterofermentative Cheddar Cheese Nonstarter Lactobacilli Species On Ribose And Galactose, Western Dairy Center, Utah State University, Megan Jane Ostler, Jeff Broadbent, Craig J. Oberg, Donald J. Mcmahon

Nutrition, Dietetics, and Food Sciences Faculty Publications

An obligatory heterofermentative lactic acid bacterium, Lactobacillus wasatchii sp. nov., isolated from gassy Cheddar cheese was studied for growth, gas formation, salt tolerance, and survival against pasteurization treatments at 63°C and 72°C. Initially, Lb. wasatchii was thought to use only ribose as a sugar source and we were interested in whether it could also utilize galactose. We conducted experiments to determine the rate and extent of growth and gas production in carbohydraterestricted (CR) de Man, Rogosa, and Sharpe (MRS) medium under anaerobic conditions with various combinations of ribose and galactose at 12, 23, and 37°C, with 23°C being the optimum …

When You Can't Watch What You Eat: Examining The Fda’S Recall Process For Food Allergies, Jacob Passy

Capstones

Over a third of all recalls for food products in the United States occur due to an undeclared allergen. In these situations, a food product is often mislabeled or contaminated in some way, resulting in the unknown presence of allergen. For food-allergic consumers, a company's mistake can become life-threatening. By investigating data from the Food and Drug Administration, I found that supermarket chains are responsible for about a fifth of all recalls, and that many recalls occur past the product's expiration date. These factors point to the need to improve the FDA's handling of food allergies in food manufacturing.

The Wild West Of Edible Insects, Kyle Ligman

Capstones

After the UN came out with a report in 2013 recommending insects for human consumption, businesses and restaurants in the U.S. have been racing to grow a new industry. This project explores the psychological, regulatory and production challenges they face.